要获取所有数据库的列表，您需要使用以下语法-
use admin
db.runCommand({listDatabases: 1});要获取特定数据库的所有集合名称的列表，您需要使用以下语法-
use yourDatabaseName; db.getCollectionNames();
让我们实现以上语法-
情况1-获取数据库列表
> use admin
switched to db admin
> db.runCommand({listDatabases: 1});这将产生以下输出-
{
"databases" : [
{
"name" : "admin",
"sizeOnDisk" : 1675264,
"empty" : false
},
{
"name" : "config",
"sizeOnDisk" : 131072,
"empty" : false
},
{
"name" : "local",
"sizeOnDisk" : 77824,
"empty" : false
},
{
"name" : "main",
"sizeOnDisk" : 184320,
"empty" : false
},
{
"name" : "my",
"sizeOnDisk" : 753664,
"empty" : false
},
{
"name" : "sample",
"sizeOnDisk" : 1286144,
"empty" : false
},
{
"name" : "sampleDemo",
"sizeOnDisk" : 352256,
"empty" : false
},
{
"name" : "studentSearch",
"sizeOnDisk" : 262144,
"empty" : false
},
{
"name" : "test",
"sizeOnDisk" : 15810560,
"empty" : false
},
{
"name" : "university",
"sizeOnDisk" : 229376,
"empty" : false
},
{
"name" : "web",
"sizeOnDisk" : 217088,
"empty" : false
}
],
"totalSize" : 20979712,
"ok" : 1
}情况2-获取收藏列表
在这里，我们获取数据库“样本”的集合列表
> use sample; switched to db sample > db.getCollectionNames();
这将产生以下输出-
[ "arraySizeErrorDemo", "basicInformationDemo", "copyThisCollectionToSampleDatabaseDemo", "documentWithAParticularFieldValueDemo", "employee", "findListOfIdsDemo", "findMimimumElementInArrayDemo", "findSubstring", "getAllRecordsFromSourceCollectionDemo", "getElementWithMaxIdDemo", "insertDocumentWithDateDemo", "internalArraySizeDemo", "largestDocumentDemo", "makingStudentInformationClone", "nestedArrayDemo", "oppositeAddToSetDemo", "prettyDemo", "returnOnlyUniqueValuesDemo", "selectItemDemo", "selectWhereInDemo", "sourceCollection", "specificFieldDemo", "studentInformation", "sumOfValueDemo", "sumTwoFieldsDemo", "truncateDemo", "updateFieldIfValueIsGreaterDemo", "updateInformation", "userInformation" ]